Beverage preparation devices designed for dispensing beverages are well-known and commonplace in both domestic and commercial environments. These devices are generally configured for preparing cold or hot beverages on-demand such as in particular a coffee or tea beverages in case the device comprises a heating unit, or chilled drinks such as in particular soft drinks or water. In the later case, the device may be equipped with a refrigeration unit.
A common principle in this field is the beverage preparation by means of an ingredients containing cartridge or capsule, which is inserted into dedicated receiving means of the device and from which a beverage is prepared by provision of liquid into the cartridge. Thereby, a predefined amount of liquid at a desired flow rate and pressure is provided to the capsule in order to interact with the ingredients contained therein, such as e.g. by extraction or by brewing. The resulting beverage is then preferably directly poured from the cartridge into a provided receiving vessel.
The known beverage preparation devices usually implement a fluid circuit such as schematically indicated in FIG. 7. Thereby, a water supply tank 10 of the device 100a is connected to a pump 106 and a flow meter 30 detecting the flow rate and volume of liquid through a tubing interconnecting the pump 106 and the water supply 10. A water filter 20 may be placed in the fluid path between supply 10 and pump 106. The device may comprise a heating unit such as a thermoblock 112 arranged in the fluid path from pump 106 to a receiving chamber 118 for receiving and holding a cartridge 40 containing beverage ingredients. A liquid beverage poured from the cartridge 40 is received in a receiving cup 70. The pump as used in these devices is generally a solenoid pump such as for example described in European application EP 2 107 242 A1.
In the known devices such as EP 2 107 242 A1, control of the water flow rate and thus amount of liquid provided into the receiving chamber containing the cartridge is usually obtained by activation of the pump based on a phase angle control of the provided current and provision of a feedback loop between the flow meter and the pump which enables the adjustment of the phase angle control based on the effective measurement of the flow rate and/or amount of liquid already provided to the receiving chamber.
Due to increasing requirements regarding miniaturizing of the beverage preparation device size and reduction of manufacturing costs, it is desired to reduce the number of components in the device. In view of these demands a solution is sought-after which enables an enhanced control of the flow rate and thus liquid volume provided by the pump of the device in a given time but without the provision of a dedicated flow meter in the fluid circuit of the device. Thereby, it is further desired to provide a reliable control of the fluid flow rate provided to the cartridge of the device in order to maintain a reproducible and optimum result regarding strength and volume of the resulting beverage.
Further, as the activation and deactivation of the pump in irregular manner may lead to unpleasant sound due to the pumping member interacting with a stop member or frame of the solenoid pump, an essential homogenous activation of the pump is desired.
The present invention provides a solution to the before-mentioned problems and offers additional benefits to the existing art as will be apparent in the following description.